Abstract
Purpose: :
The objective of the investigation was to evaluate the incidence and type of the lid margin staining of contact lens wearers who attended OTG R&C Clinic.
Methods: :
The study population of 183 consecutive contact lens wearers (82 Male, 101 Female) aged between 18 and 79 years (Mean 33 ± 12 years) includes both asymptomatic and symptomatic wearers as per the OSDI questionnaire; the subjects either attended the clinic wearing contact lenses or had not worn contact lenses on the day of the visit. Upper and lower lid margin staining was evaluated with lissamine green using X16 magnification under direct illumination with a diffuser. Lid margin staining was judged in terms of Staining Type (4-point scale: 0 =None, 1 = Broken line, 2 = Thin line, 3 = Thick line/Patch) and Staining Severity (5-point scale: 0 = None,1 = Slight, 2 = Mild, 3 = Moderate, 4 = Severe).
Results: :
The results obtained showed that:i. Lid margin staining was in the majority of cases rated as Mild or Moderate for both the upper (Mild=46% Moderate=35%) and lower (Mild=39% Moderate=39%) eyelids.ii. The staining observed was most commonly of the "Thin line" type (Upper Lid =66% Lower Lid =62%) and clinically significant "Thick line/patch" in over 1 in 5 eyelid (Upper = 21% Lower = 22%).iii. The staining was highly correlated between the upper and lower lid margins (Type r = 0.808; severity r = 0.855)iv. Contact lens wear at the time of the visit was not a significant factor (p = 0.056 to 0.934).v. The type of staining observed was similar for symptomatic and asymptomatic wearers (p = 0.198 & 0.460), but the severity was significantly greater for the symptomatic wearers (p = 0.001 & <0.001).
Conclusions: :
The presence of lid margin staining is a normal feature which represents the line of contact between the lid margin and the ocular surface / contact lens, however, in one in five eyes, the area of staining is enlarged. The absence of a difference in staining, whether contact lenses were worn at the time of the visit or not, suggests that any effect associated with long term contact lens wear does not recover overnight. Finally, symptomatic contact lens wearers exhibited higher levels of both upper and lower lid margin staining than asymptomatic wearers.
Keywords: conjunctiva • cornea: tears/tear film/dry eye • contact lens